This invention relates to heat sinks and methods of attaching heat sinks to objects from which heat is to be removed.
It is very important to have a good thermal interface between a heat sink and the object from which heat is to be removed. Usually this is accomplished by manufacturing both pieces to have flat heat sink surfaces and by fastening them tightly together. Often a thermal compound is used to fill any gaps between the flat heat sink surfaces.
To have stable flat surfaces, both the heat sink and the object from which heat is to be removed must have substantial strength and mechanical integrity. In many cases the heat sink is an aluminum extrusion of substantial thickness. Sometimes it is a casting having a machined heat sink surface, or a fabricated part such as a heavy copper plate with a plurality of fins brazed or bonded therein. It is usually necessary to machine the heat sink surface to ensure good thermal contact.
This invention teaches that the heat sink and/or the object from which heat is to be removed may have significant flexibility. Indeed, it may be advantageous for one or both to have significant flexibility in that it allows good conformity for good thermal contact even if one or the other is uneven.
The heat sink is attached to the object from which heat is to be removed with a good adhesive or solder under vacuum or with external pressure.
The flexible heat sink of this invention may be much smaller and lighter in weight than a conventional heat sink. It may use less material and have less stringent machining requirements, so it may be much more economical to fabricate and use.
Because a vacuum is used to pull the interface together at all points, there are fewer gaps or voids and the adhesive layer may be much thinner, for improved heat conduction. The amount of excess adhesive drawn from the interface may be a good indicator of the interface integrity.